System for distributed spectrum sensing in a highly mobile vehicular environment

Abstract

A system and method for detecting spectrum holes in a region is disclosed. The system comprises a requesting module, a detecting module and an aggregation module. The requesting module retrieves channel availability data for a region. The channel availability data describes potential availability of a channel. The detecting module obtains a set of values for the channel by spectrum sensing at a set of locations in the region based at least in part on the potential availability of the channel. The aggregation module aggregates the set of values for the channel over the set of locations in the region to obtain a first value for the channel and determines the availability of the channel based at least in part on the first value for the channel.

What is claimed is: 
     
       1. A computer-implemented method for determining availability of a channel, the method comprising:
 retrieving channel availability data for a region, the channel availability data describing potential availability of a channel; 
 obtaining a set of values for the channel by spectrum sensing at a set of locations in the region based at least in part on the potential availability of the channel; 
 aggregating the set of values for the channel over the set of locations in the region to obtain a first value for the channel; and 
 determining the availability of the channel based at least in part on the first value for the channel. 
 
     
     
       2. The method of  claim 1 , wherein a value in the set of values indicates a state of a primary user for the channel at a location in the set of locations. 
     
     
       3. The method of  claim 2 , wherein the state of the primary user for the channel comprises one or more of a presence and an absence. 
     
     
       4. The method of  claim 1 , wherein a value in the set of values indicates a signal power for the channel at a location in the set of locations. 
     
     
       5. The method of  claim 1 , wherein locations in the set of locations are geographically close to each other. 
     
     
       6. The method of  claim 1  further comprising:
 weighing values in the set of values for the channel based at least in part on locations in the set of locations that the values correspond to. 
 
     
     
       7. The method of  claim 1  further comprising:
 broadcasting data describing the first value for the channel. 
 
     
     
       8. The method of  claim 1  further comprising:
 receiving data describing a second value for the channel; and 
 aggregating the second value for the channel with the first value for the channel to determine the availability of the channel. 
 
     
     
       9. A system for determining availability of a channel, the system comprising:
 a requesting module for retrieving channel availability data for a region, the channel availability data describing potential availability of a channel; 
 a detecting module communicatively coupled to the requesting module, the detecting module obtaining a set of values for the channel by spectrum sensing at a set of locations in the region based at least in part on the potential availability of the channel; and 
 an aggregation module communicatively coupled to the detecting module, the aggregation module aggregating the set of values for the channel over the set of locations in the region to obtain a first value for the channel, the aggregation module also determining the availability of the channel based at least in part on the first value for the channel. 
 
     
     
       10. The system of  claim 9 , wherein a value in the set of values indicates a state of a primary user for the channel at a location in the set of locations. 
     
     
       11. The system of  claim 10 , wherein the state of the primary user for the channel comprises one or more of a presence and an absence. 
     
     
       12. The system of  claim 9 , wherein a value in the set of values indicates a signal power for the channel at a location in the set of locations. 
     
     
       13. The system of  claim 9 , wherein locations in the set of locations are geographically close to each other. 
     
     
       14. The system of  claim 9 , wherein the aggregation module further weighs values in the set of values for the channel based at least in part on locations in the set of locations that the values correspond to. 
     
     
       15. The system of  claim 9  further comprising a collaboration module communicatively coupled to the aggregation module, the collaboration module broadcasting data describing the first value for the channel. 
     
     
       16. The system of  claim 9  further comprising a collaboration module communicatively coupled to the aggregation module, the collaboration module receiving data describing a second value for the channel and aggregating the second value for the channel with the first value for the channel to determine the availability of the channel. 
     
     
       17. A computer program product comprising a non-transitory computer readable medium encoding instructions that, in response to execution by a computing device, cause the computing device to perform operations comprising:
 retrieving channel availability data for a region, the channel availability data describing potential availability of a channel; 
 obtaining a set of values for the channel by spectrum sensing at a set of locations in the region based at least in part on the potential availability of the channel; 
 aggregating the set of values for the channel over the set of locations in the region to obtain a first value for the channel; and 
 determining the availability of the channel based at least in part on the first value for the channel. 
 
     
     
       18. The computer program product of  claim 17 , wherein a value in the set of values indicates a state of a primary user for the channel at a location in the set of locations. 
     
     
       19. The computer program product of  claim 18 , wherein the state of the primary user for the channel comprises one or more of a presence and an absence. 
     
     
       20. The computer program product of  claim 17 , wherein a value in the set of values indicates a signal power for the channel at a location in the set of locations. 
     
     
       21. The computer program product of  claim 17 , wherein locations in the set of locations are geographically close to each other. 
     
     
       22. The computer program product of  claim 17 , wherein instructions encoded in the non-transitory computer readable medium when executed cause the computing device to perform operations further comprising:
 weighing values in the set of values for the channel based at least in part on locations in the set of locations that the values correspond to. 
 
     
     
       23. The computer program product of  claim 17 , wherein instructions encoded in the non-transitory computer readable medium when executed cause the computing device to perform operations further comprising:
 broadcasting data describing the first value for the channel. 
 
     
     
       24. The computer program product of  claim 17 , wherein instructions encoded in the non-transitory computer readable medium when executed cause the computing device to perform operations further comprising:
 receiving data describing a second value for the channel; and 
 aggregating the second value for the channel with the first value for the channel to determine the availability of the channel.